Interpretive Summary: Proanthocyanidins (PAs) belong to a subclass of flavonoids. They are also called "Condensed Tannins" and may impart astringent flavor to foods. They are common in many plant foods such as fruits, grains, and beverages like wine and tea, and some chocolates. Most of the vegetables do not contain PAs. They share many biological properties, such as antioxidant activities, of other flavonoid classes and may improve peripheral blood circulation. Particular types of PAs protect against urinary tract infections. USDA's Nutrient Data Laboratory scientists have developed a database for proanthocyanidin contents in selected foods to help study the associations between intakes of PAs with the improved health status. Nationally representative samples of 29 fruits, 8 nuts, 2 kinds of beans, 1 vegetable, and 3 kinds of chocolates procured under the NDL's National Food and Analysis Program (NFNAP) were analyzed by ARS scientists at the Arkansas Children's Nutrition Center. In addition, data were collected by reviewing and evaluating scientific literature. The database contains mean, standard deviation, minimum and maximum values per 100g edible portions in each food for 206 foods. The data quality evaluation results (Confidence Codes) and data sources (references) are provided for each value. These results will help set priorities for future research needs. The PA database, released in August 2004, will complement the databases for flavonoids and isoflavones also available on NDL's web site: http//www.nal.usda.gov/fnic/foodcomp.

Technical Abstract:
Proanthocyanidins (PAs), the polymers of flavan-3-ols, are also referred to as "Condensed Tannins". The most common flavanol linkages are C-C bonds (B-Type, 4-6 or 4-8), but occasionally mixed double linkages (A Type, 4-8, 2-7) do occur. They are common in many plant foods such as fruits, grains, and beverages like wine and tea and some chocolates. Most of the vegetables do not contain PAs.Procyanidins are the major compounds, sometimes mixed with prodelphinidins, in foods. It has been hypothesized that the free radical scavenging properties of PAs may improve peripheral circulation and may inhibit platelet function (anticoagulant). They may help protect against urinary tract infections and improve glucose uptake. These last two functions are attributed to the A-type linkages of flavanols. Therefore a food composition database for proanthocyanidins in foods is required to investigate these associations between proanthocyanidin intakes and improved health status. The USDA scientists along with scientists in academia and industry have developed a database for proanthocyanidins in selected foods. Nationally representative samples of 29 fruits, 8 nuts, 2 kinds of beans, 1 vegetable and 3 kinds of chocolates procured under the NDL's National Food and Analysis Program (NFNAP) were analyzed by ARS scientists at the Arkansas Children's Nutrition Center using normal phase High Performance Liquid Chromatography (HPLC) method. In addition, quantitative analytical data from literature were also collected. The quality of these data was evaluated by the criteria developed by NDL scientists. Approximately 30 articles out of the 66 retrieved, contained acceptable analytical data. The database contains values for 206 foods. The mean, standard deviation, minimum and maximum values for flavan-3-ol monomers, PA dimers, trimers, 4-6mers (tetramers, pentamers and hexamers together), 7-10mers (heptamers, octamers, nonamers and decamers together), and polymers (degrees of polymerization, DPs > 10), for every food, whenever available, are reported in the database along with the confidence codes and sources of data. The values are reported as mg/100g of edible portion. Two separate tables for foods with no detectable quantities of PAs and foods with a mix of procyanidins, prodelphinidins and propelargonidins and also A-Type linkages are attached. The PA database, released in August 2004, will complement the earlier databases for flavonoids and isoflavones also available on NDL's web site: http//www.nal.usda.gov/fnic/foodcomp.